Conservatives have been trying to crack the code for a number of years on how to get Jewish voters over to their side. Based on the findings of the new "Portrait of Jewish Americans" survey from the Pew Research Center, Republicans will need to find a different key. Jews are likely going to be Democrats for the foreseeable future.

Let's start with the fact that the most important determining factor of voting pattern is partisan affiliation. If you identify as a Democrat, you are far more likely to vote Democratic than if you identify as an independent or a Republican. In this instance, 70% of Jews self-identify as leaning to or members of the Democratic party. That compares with just 49% of the American public overall who at least lean Democratic. Only 22% of Jews consider themselves as leaning Republican, compared to 39% of the overall public. Orthodox Jews, who represent no more than 10% of the United States' Jewish population, tend to make up the majority of Republican Jews.

Given their self-identification, it's unlikely that Jewish Americans will break from their Democratic ways. But a closer look at why Jews are Democratic should give Republicans further pause.

US Jews are very liberal: 49% of Jewish adults identify as liberal, compared with just 19% who say they are conservative. That's nearly a mirror-opposite of the general public, of whom 38% say they are conservative and 21% say they are liberal. That finding holds for age groups, albeit that Jews become less liberal as you look at the spectrum from Reform towards Orthodox.

The reason American Jews are liberal is because they tend to sympathize with the less fortunate and with minorities: like many black and Hispanic Americans, 54% of Jews believe government should be bigger, with more services, compared to just 40% of the public at large who believe the same. And 82% of Jews think that homosexuality should be accepted by society, while just 57% of the general public believes so.

Tellingly, Jews sound a lot more like a minority when it comes to discrimination than one might expect from a group of people who are mostly white. Despite problems between Israel and its Arab (and Persian) neighbors, 72% of Jews say Muslims in America are discriminated against, versus just 47% of the public at large who say that. While 64% of Jews say there is discrimination against African Americans, only 47% of all Americans do. This gap extends to attitudes towards Latino Americans, as well.

The roots of these liberal values probably lie in Jews' own understanding of what they went through in their history, with 73% of Jews holding the belieef that remembering the Holocaust is an essential part of being Jewish. Indeed, Jews say it is the most essential part of what it means to be Jewish. Third on the list, though, at 56%, is working for justice and equality.

It's unlikely that outreach by religious Christians, who tend to be very conservative, on the issue of Israel is going to break this pattern. Jews simply don't feel any real affinity towards Evangelical Christians. Jews, for instance, don't buy into the idea that there is a (secularist) war against Christianity, as Rand Paul has argued. Only 16% of Jews agree there is discrimination against Evangelical Christians in the United States (a much larger 30% of all Americans think there is).

On the issue of Israel, only 40% of Jews believe God "gave them Israel". This percentage is lower than the general public's belief (at 44%) and far below white Evangelicals' 82% conviction. Other data indicate that Jews wouldn't be likely to follow anyone who tried use Israel as a wedge issue to separate Jews and their Democratic inclinations.

While it's true that 69% of Jews, including at least 60% of all age groups, feel an attachment to Israel, the problem for Republican recruiters is that only 43% of Jews believe that caring about Israel is an essential part of being Jewish. That's far lower than the percentage who say the same thing for remembering the Holocaust or working for justice and equality.

Perhaps most telling is that most Jews don't feel the United States needs to be closer to Israel: nearly two-thirds (65%) of Jewish Americans feel that US support for Israel is either "about right" or too much. This holds across all age groups, and it's matches attitudes in the population at large. In fact, Jewish voters are 19pt more likely to say they support Obama's handling the US policy towards Israel than all Americans.

When you put it all together, Jewish voters are Democratic for a reason. They believe in the party's liberal ideology, and identify with its core values. They will not be swayed by Republican attempts to switch allegiances, because on the key issue on which the GOP (partly under Evangelical influence) highlights – diehard support for Israel – just doesn't impress Jews much. They don't view Israel as essential to their political allegiances in the United States, and even if they did, they think Democratic policy is just fine.

• This sixth paragraph of this article received a minor amendment for the sake of clarity at 3.45pm (ET) on 2 October